If meta(3)>0 then make the database readonly for now. This allows the current
database to interact with future releases that might include autovacuum. (CVS 1888)
(check-in: 7619bf47 user: drh tags: trunk)

Separate P4 timing asm code out of the SQLITE_DEBUG macro so that SQLITE_DEBUG
can be used on non-x86 machines and with compilers other than GCC.
Ticket #838. (CVS 1876)
(check-in: add266cc user: drh tags: trunk)